Nelson
press unloader



H. J. NELSON PRESS UNLOADER Oct. 311, 1967 2 Sheets-Sheet 1 Filed Aug. 31, 1965 INVENTOR. Harvey J. Nelson. BY

A TmQ/vEs Oct. 31, 1967 H. J. NELSQN 3,349,602

PRES S UNLOADER Filed Aug. 31, 1965 2 Sheets-Sheet 2 ,INVENTOR.

HarveylNeIsom. Y

' ATTORNEY United States. Patent 3,349,602 PRESS UNLOADER Harvey J. Nelson, Warren, Mich., assignor to The Budd Company, Philadelphia, Pa., a corporation of Pennsylvama Filed Aug. 31, 1965, Ser. No. 483,926 6 Claims. (Cl. 72-426) This invention relates to a press unloader which presents an article-receiving element into position to receive an article or workpiece when the press parts separate, and has for an object the provision of improvements in this art.

It is now well recognized that wherever possible power presses should be equipped with serving and unloading mechanisms to minimize danger to the operator and lighten his work. Many press unloaders have been proposed. Some use separate prime power actuators but this is involved and expensive and employs timing devices which may get out of phase. Some use separable striker-type mechanisms which wear rapidly and are subject to breakage due to suddenly imposed heavy loads. Some use slotand-pin type linkages which wear rapidly. Some use swingtype work-piece receiving elements which often obstruct access to the working area of the press. Other types of unloaders and their points of unsuitability for present purposes might be discussed but the above-mentioned types are sufiicient to aid in an understanding of the objects and advantages of the present invention.

One of the specific objects of the present invention is to provide a press unloader with a workpiece receiving element which reciprocates in and out of the working space of the press, preferably on an inclined line which provides that the workpiece will slide completely out of the press area after delivery.

'Another object is to provide a press unloader which does not obstruct access to the working area of the press when the workpiece receiving element is retracted.

Another object is to provide apress unloader which is operated directly by the press itself; which has linkage which is always connected; and has simple linkage with pin-and-bearing joints which have long wear life as compared to pin-and-slot joints and separable striker-type parts.

Another object is to provide simple, accessible, and easily adjustable mechanism for fitting the action of the unloader to the action of the press.

The above and other objects of the invention, as well as various features of novelty and advantages, will be apparent from the following description of an exemplary embodiment, reference being made to the accompanying drawings, wherein:

FIG. 1 is a side elevation of the mid-portion of a press equipped with an unloader embodying the present invention;

FIG. 2 is a front elevation of the press unloader alone.

As shown in the drawings, a power press has a fixed lower part 11 with a die 12 and a reciprocable upper part 13, known as a ram or head, with a die 14. The workpiece formed by the press is not shown for purposes of discussion it maybe assumed to be a drum back for automobile drum brakes and it may further be assumed that after it has been formed on the downstroke of the upper die it is raised with the upper die and is automatically ejected from the upper die when it has reached its top position and the workpiece-receiving element of the press unloader has been introduced into workpiece-receiving position.

The workpiece-receiving element illustrated comprises a tray 16 which at each side is provided with projecting pins or axle shafts 17 carrying rollers 18 which operate in slotted trackways 19 secured, as by welded-on brackets 20, to fixed upstanding frame members 21. As shown in FIG. 2, there is a fixed frame member 21 at each side of the press and when the tray is retracted the working space at the press is free for access. The workpiece is inserted from a side of the press not occupied by the unloader, either manually or by automatic means, but it is not necessary for present purposes to know further details of the press or its operation.

The tray is strengthened by ribbing 23 under its bottom and at the front end of the upper side is' provided with an upturned flange 24 to forcibly pull back a workpiece if necessary. Longitudinal side flanges 25 are provided for retaining the workpiece in position on the tray. As shown, the tray is mounted on an inclination, as a chute, so the workpiece will slide downward and outward as soon as it is ejected onto the upper or front end of the tray. A'delivery slide conveyor or chute 26, positionally shown in FIG. 1, may be provided for removing workpieces from the delivery zone; or, alternatively, a travelling box container may be disposed in position to receive workpieces from the lower end of the tray.

The means for reciprocating the tray at each stroke of the movable press head comprises, at each side of the tray, a bifurcated arm 30 having a bearing 31 tumably mounted on the lower one of the tray supporting shafts 17.

To each tray actuating arm 30 there is connected, as by a pivot pin 32, the outer end of a swingable arm 33 which is rigidly secured to a strong transverse shaft 34 which, at its ends, is mounted in bearing blocks 35 secured, as by bolts 36, to a side bar 37, which, in turn, is secured to the side frame members 21, as by bolts 38.

At the point along the arms 33 there is pivotally connected, as by a pivot pin 40, a bifurcated member or clevis 41, in the outer end of which there is threaded for adjustment a screw link 42 which, at its other end, is secured, as by welding, to bifurcated member or clevis 43. For quicker adjustment a right-left threaded turnbuckle-type rod with locknuts could be used instead of a rod threaded only at one end. The clevis members 43 are pivotally connected, as by a pivot pin 44, to the outer end of an arm 45 which comprises part of a bellcrank lever 46 which is secured to a strong cross shaft 47 mounted at its ends in fixed bearings 48. The bearings are secured, as by bolts 49, to the side bars 37, which, as before, are secured to the frame members by bolts 38.

The other arm 53 of the bellcrank lever 46 of this linkage is pivotally connected, as by a pivot pin 54, to a twobar link 55 which, at its upper end, is pivotally connected, as by a pivot pin 56, to a bracket 57 which is secured, as by screws 58, to the movable press head 13. The brackets 57 are provided with a plurality of holes 60, for the pin 56, and these selective connections together with the adjustable links 42, provide a wide range of adjustment for the movement of the tray.

From FIG. 1 it can be noted that the swingable end of the arm 30, which is connected to the tray to reciprocate it, swings through an arc which is almost symmetrical on the axis of the track on which the tray slides; also that at each end of the stroke the arm 30 lies approximately parallel to the axis of the track.

The swingable end of the arm 53, which is connected to the movable press head, swings through an are which is almost symmetrical on the vertical axis of the press head; and that the link at each end of the stroke makes almost the same angle relative to the axis of the press head.

The two large shafts 34 and 47 for the two lever systems, which are connected by the adjustable link 42, lie almost in a horizontal line and can conveniently be mounted on the generally horizontal side bars 37.

If the link 42 is lengthened the end of the tray is moved back, that is, it does not move so far into the press opening; and if it is shortened the end of the tray is moved further into the press space.

Similarly, if the upper end of link 55 is connected with a lower hole 60 the end of the tray is moved back; and if it is connected with an upper hole 60 the end of the tray is moved further into the press space. The holes 60 in an upward direction are progressively spaced further from the vertical axis of the press head to keep link 55 at nearly the same angle relative to the axis of the press head for different adjusted positions.

It will also be noted that the entire linkage system between the press head and the tray is located almost completely in the angle between the press head and the tray. This keeps other areas clear of the tray operating mechanism and disposes it where it is accessible for servicing. Also, because the linkage system is a dual one with duplicated mechanisms at each side of the tray, the action is even and smooth and the space between is left clear for access or sight to the press zone when the tray is in the retracted position.

It is thus seen that the invention provides simple, convenient and long-wearing press unloading mechanism which is easy to install and service and which does not unduly obstruct view and access to the press space. The adjusting means which are incorporated provide simple and convenient change of the operating range and stroke of the tray.

While one embodiment of the invention has been described for purposes of illustration, it is to be understood that there may be various embodiments and modifications within the general scope of the invention.

What is claimed is:

1. Press unloading apparatus comprising in combination, a lower press part and die, an upper press part with a vertically movable head having a die and ejector means for holding a formed workpiece on its upstroke and ejecting it near the end of the upstroke, an unloader tray mounted for movement into and out of workpiece-receiving position between the dies, and operating linkage mechanism arranged between said head and said tray for moving the tray under the upper die when the head is in its upper position and withdrawing the tray when the head moves downward, said linkage mechanim comprising a first connecting link pivotally connected to said head at its upper end, a first swinging arm mounted to turn about a first fixed pivot axis and pivotally connected at its outer end to said first link, a second swinging arm mounted to turn about said first fixed pivot axis with said first swinging arm, a second connecting link pivotally connected to said second swinging arm at one end, a third swinging arm mounted to turn about a second fixed pivot axis spaced horizontally from said first fixed pivot axis and pivotally connected at its outer end to said second connecting link, a fourth swinging arm mounted to turn about said second pivot axis with said third swinging arm, and a fifth swinging arm pivotally mounted on a axis on said tray and pivotally connected at its outer end of the outer end of said fourth swinging arm.

2. Press unloading apparatus as set forth in claim 1, further characterized by the fact that said operating linkage mechanism is duplicated at opposite sides of the tray and that said tray is mounted to reciprocate in upwardly and inwardly inclined guides, leaving the press area between dies open for view and access when the inclined tray is retracted.

3. Press unloading mechanism as set forth in claim 1, further characterized by the fact that said second connecting link is adjustable in length.

4. Press unloading mechanism as set forth in claim 1, further characterized by the fact that said first connecting link is adjustably connected for securement at different vertical positions to said head.

5. Press unloading mechanism as set forth in claim 3, further characterized by the fact that said first connecting link is adjustably connected for securement at different vertical positions to said head.

6. Press unloading mechanism as set forth in claim 4, further characterized by the fact that the pivot connection of the first connecting link is adjusted outwardly in a direction away from said head as its pivot axis is adjusted upwardly.

References Cited UNITED STATES PATENTS 2,314,120 3/1943 Braun 72426 X 2,763,229 9/1956 Sahlin 72426 2,802,381 8/1957 Leasia 72427 2,867,185 1/1959 Hayward 72426 2,943,750 7/.l960 Sehn et al 72426 X 3,148,571 9/1964 Wallis 72426 X CHARLES W. LANHAM, Primary Examiner. 

1. PRESS UNLOADING APPARATUS COMPRISING IN COMBINATION, A LOWER PRESS PART AND DIE, AN UPPER PRESS PART WITH A VERTICALLY MOVABLE HEAD HAVING A DIE AND EJECTOR MEANS FOR HOLDING A FORMED WORKPIECE ON ITS UPSTROKE AND EJECTING IT NEAR THE END OF THE UPSTROKE, AN UNLOADER TRAY MOUNTED FOR MOVEMENT INTO AND OUT OF WORKPIECE-RECEIVING POSITION BETWEEN THE DIES, AND OPERATING LINKAGE MECHANISM ARRANGED BETWEEN SAID HEAD AND SAID TRAY FOR MOVING THE TRAY UNDER THE DIE WHEN THE HEAD IS IN ITS UPPER POSITION AND WITHDRAWING THE TRAY WHEN THE HEAD MOVES DOWNWARD, SAID LINKAGE MECHANISM COMPRISING A FIRST CONNECTING LINK PIVOTALLY CONNECTED TO SAID HEAD AT ITS UPPER END, A FIRST SWINGING ARM MOUNTED TO TURN ABOUT A FIRST FIXED PIVOT AXIS AND PIVOTALLY CONNECTED AT ITS OUTER END TO SAID FIRST LINK, A SECOND SWINGING ARM MOUNTED TO TURN ABOUT SAID FIRST FIXED PIVOT AXIS WITH SAID FIRST SWINGING ARM, A SECOND CONNECTING LINK PIVOTALLY CONNECTED TO SAID SECOND SWINGING ARM AT ONE END, A THIRD SWINGING ARM MOUNTED TO TURN ABOUT A SECOND FIXED PIVOT AXIS SPACED HORIZONTALLY FROM SAID FIRST FIXED AXIS AND PIVOTALLY CONNECTED AT ITS OUTER END TO SAID SECOND CONNECTING LINK, A FOURTH SWINGING ARM MOUNTED TO TURN ABOUT SAID SECOND PIVOT AXIS WITH SAID THIRD SWINGING ARM, AND A FIFTH SWINGING ARM PIVOTALLY MOUNTED ON A AXIS ON SAID TRAY AND PIVOTALLY CONNECTED AT ITS OUTER END OF THE OUTER END OF SAID FOURTH SWINGING ARM. 